COLLAGEN INDUCES CYTOKINE PRODUCTION BY SYNOVIAL-FLUID MONONUCLEAR-CELLS IN RHEUMATOID-ARTHRITIS

Synovial fluid (SF) mononuclear cells (MNC) from 13 patients with rheu matoid arthritis (RA) and 12 patients with other arthritic diseases (O D) including osteoarthritis (OA), gout and spondyloarthritis (SA) were cultured in the presence of collagen types I and II or lipopolysaccha ride (LPS) for 24 h. Interleukin-l (IL-1), IL-6 and tumor necrosis fac tor-alpha (TNF-alpha) in the SF and culture supernatants were assayed using ELISA. The results showed that one-half of the RA patients with high SF monocyte count had high SF IL-6 levels that coincided with the high spontaneous release of IL-6 by SF MNC. In the other RA patients with lower SF monocyte count, type II collagen induced significantly h igher IL-1(beta) than the medium control levels by SF MNC (P < 0.01) o r that of the other diseases (P < 0.01). Similarly, type II collagen-i nduced IL-6 and TNF-a production rose significantly (P < 0.01) from SF MNC of RA but less from OD (P < 0.05). In addition, type I collagen c ould also induce IL-1, IL-6 and TNF-alpha in these samples from RA and OD patients but was less potent than type II collagen. Our results in dicate that collagen-induced cytokines may be important in the pathoge nesis of the disease.